Signal transmission and reception using multiple antennas

Abstract

In an exemplary embodiment, a network node can receive signals from user devices in a wireless communication network. The network node can combine the signals received at each receive antenna of the network node based on vectors from a pre-defined set of vectors. The network node can also process the combined signals to obtain an estimate of the signals.

What is claimed is: 
     
       1. A wireless communication method, comprising:
 receiving, by a network node, signals from user devices in a wireless communication network; 
 obtaining combined signals by combining, based on vectors from a pre-defined set of vectors, the signals received by the network node; and 
 processing the combined signals to obtain an estimate of the signals, wherein the processing of the combined signals comprises:
 de-spreading each combined signal using each spreading code from a set of pre-determined spreading codes; 
 performing equalization on each de-spread combined signal to obtain a set of equalized combined signals; 
 selecting a subset of equalized combined signals based on signal-to-interference-plus-noise ratio (SINR) values; and 
 decoding the selected equalized combined signals to obtain the estimate of information bits received from the user devices. 
 
 
     
     
       2. The wireless communication method of  claim 1 , wherein each vector corresponds to a code having a length equal to a number of receive antennas of the network node. 
     
     
       3. The wireless communication method of  claim 1 , wherein the combining the signals comprises:
 determining a weighted sum of the signals received from a plurality of receive antennas of the network node by a corresponding code of each vector. 
 
     
     
       4. The wireless communication method of  claim 1 , wherein the processing of the combined signals comprises:
 performing differential decoding on each combined signal; 
 selecting a subset of differential decoded combined signals based on signal-to-interference-plus-noise ratio (SINR) values; and 
 decoding the selected differential decoded combined signals to obtain the estimate of information bits received from the user devices. 
 
     
     
       5. The wireless communication method of  claim 1 ,
 wherein the signals include reference signals, and 
 wherein the processing of the combined signals comprises:
 estimating a combined channel by using the reference signals in each combined signal; and 
 processing the combined signals using a previous estimate of the combined channel. 
 
 
     
     
       6. A wireless communication method, comprising:
 generating a transmission signal to transmit from a user device in a wireless communication network,
 wherein the transmission signal includes data for processing by vectors from a set of pre-defined vectors, 
 wherein the transmission signal is generated using an access signature selected by the user device, 
 wherein the transmission signal is transmitted using a grant free transmission technique, 
 wherein the transmission signal includes data that is spread using a spreading code, scrambled using a scrambling code, interleaved using an interleaver, or generated using a differential encoding technique, 
 wherein the access signature includes the spreading code, the scrambling code, and the interleaver, and 
 wherein the transmission signal includes information related to the spreading code, the scrambling code, or the interleaver. 
 
 
     
     
       7. The wireless communication method of  claim 6 , wherein the access signature includes any one of a demodulation reference signal (DMRS), a preamble, a spreading sequence information, scrambling code information, interleaver information, and differential encoding information about the transmission signal. 
     
     
       8. The wireless communication method of  claim 6 , wherein the transmission signal includes a reference signal. 
     
     
       9. An apparatus for wireless communication, comprising a memory and a processor, wherein the processor reads code from the memory and implements a method comprising:
 receive, by a network node, signals from user devices in a wireless communication network; 
 obtain combined signals by combining, based on vectors from a pre-defined set of vectors, the signals received by the network node; and 
 process the combined signals to obtain an estimate of the signals, wherein the combined signals are processed by the processor configured to:
 de-spread each combined signal using each spreading code from a set of pre-determined spreading codes; 
 perform equalization on each de-spread combined signal to obtain a set of equalized combined signals; 
 select a subset of equalized combined signals based on signal-to-interference-plus-noise ratio (SINR) values; and 
 decode the selected equalized combined signals to obtain the estimate of information bits received from the user devices. 
 
 
     
     
       10. The apparatus of  claim 9 , wherein each vector corresponds to a code having a length equal to a number of receive antennas of the network node. 
     
     
       11. The apparatus of  claim 9 , wherein the signals are combined by the processor configured to:
 determine a weighted sum of the signals received from a plurality of receive antennas of the network node by a corresponding code of each vector. 
 
     
     
       12. The apparatus of  claim 9 , wherein the combined signals are processed by the processor configured to:
 perform differential decoding on each combined signal; 
 select a subset of differential decoded combined signals based on signal-to-interference-plus-noise ratio (SINR) values; and 
 decode the selected differential decoded combined signals to obtain the estimate of information bits received from the user devices. 
 
     
     
       13. The apparatus of  claim 9 ,
 wherein the signals include reference signals, and 
 wherein the combined signals are processed by the processor configured to:
 estimate a combined channel by using the reference signals in each combined signal; and 
 process the combined signals using a previous estimate of the combined channel. 
 
 
     
     
       14. An apparatus for wireless communication, comprising a memory and a processor, wherein the processor reads code from the memory and implements a method comprising:
 generate a transmission signal to transmit from a user device in a wireless communication network,
 wherein the transmission signal includes data for processing by vectors from a set of pre-defined vectors, 
 wherein the transmission signal is generated using an access signature selected by the user device, 
 wherein the transmission signal is transmitted using a grant free transmission technique, 
 wherein the transmission signal includes data that is spread using a spreading code, scrambled using a scrambling code, interleaved using an interleaver, or generated using a differential encoding technique, 
 wherein the access signature includes the spreading code, the scrambling code, and the interleaver, and 
 wherein the transmission signal includes information related to the spreading code, the scrambling code, or the interleaver. 
 
 
     
     
       15. The apparatus of  claim 14 , wherein the access signature includes any one of a demodulation reference signal (DMRS), a preamble, a spreading sequence information, scrambling code information, interleaver information, and differential encoding information about the transmission signal. 
     
     
       16. The apparatus of  claim 14 , wherein the transmission signal includes a reference signal.